Implanted medical devices utilize hermetically sealed housing to isolate the device from the body environment. Such devices require that electrical signals to be passed from within the housing to external connectors or vice-versa while maintaining hermeticity of the housing. Depending upon the configuration of the implantable device, there may be multiple electrical paths required between an electronic circuitry enclosed within the housing and the external connectors. These paths are usually electrically and mechanically integrated with the device in order to provide a safe, long-term arrangement that does not compromise hermetic housing.
The implantable medical device may include an implanted part of cochlear implant system.
Many implantable devices use feedthroughs to connect the hermetically housed electronic circuitry with implanted measuring and/or stimulating electrode and/or electromechanical actuator. However, the desirability of making the implanted medical devices smaller and/or less obtrusive raises design challenges, particularly in relation to the connecting a number of closely concentrated feedthroughs to respective wires outside the housing.
Conventionally, an operator directly welds each wire to feedthrough pin manually. The operator makes a little pearl at an edge of the wire using a torch flame. Thereafter, the operator electrically welds the pearl to the feedthrough pin with a tweezers connected to an impulse generator. Apart from operator dexterity, this implementation requires enough clearance between two neighboring feedthroughs to prevent reflection damage and weld interference. Therefore, securing a reliable weld connection between the wire and the feedthrough pin is extremely difficult when the feedthroughs that are closely concentrated in a small area.
Furthermore, there might be a risk of contact between closely welded weld-connections at neighboring feedthroughs and/or very poor yield, which is usually due to the rework required if the first welding attempt is not correct. Therefore, the classical hand wire welding and wire-by-wire welding between the closely concentrated feedthrough pins and the wire is not feasible. Also, with an increasing number of required electrical paths, there is an excess amount of the wires present in proximity to feedthroughs, and orienting the excess wires as these wires exit the medical device while maintaining the relatively small profile is also challenging.
Therefore, there is a need to provide a solution that addresses at least some of the above-mentioned problems.